Researchers have discovered a species of palm on Borneo with a very unusual reproductive strategy: In Pinanga subterranea - as it is called - both the fruit and the flowers grow underground.
"Amazingly, this remarkable species is widespread throughout western Borneo and is valued by local people for its edible fruits, but has so far completely escaped the attention of scientists," writes the team led by Agusti Randi of the National University of Singapore in its Study. The research results were published in the journal Plants People Planet.
puzzles for science
"The fruits are pale white when they are young. When they are ripe, they are then oval, about two centimeters long and bright red," said Benedikt Kuhnhauser, co-author of the study and Future Leader Fellow at the Royal Botanic Gardens in Kew/London, the German Press Agency. They tasted sweet, "a bit like wild strawberries or blueberries - only the palm tree is a lot harder to find." The flowers, on the other hand, are rather inconspicuous, greenish-white and smaller than one centimeter.
"The mysterious lifestyle of the palm tree has certainly contributed to the fact that we have only now described it scientifically," emphasized the researcher. Around 300 species of palm trees exist on Borneo and there are countless young palm sprout that are difficult to identify even for experts.
No stranger to the local population
The local population, on the other hand, had known Pinanga subterranea for a long time: "Before the underground palm was given its scientific name, it was already known in Borneo with at least four different names and in at least three different languages."
So far, only one other plant is known worldwide that forms both flowers and fruits underground: the small Australian orchid genus Rhizanthella. How pollination occurs in Pinanga subterranea is still unclear: "Closely related palms of the same genus Pinanga are quite often pollinated by beetles," says Kuhnhäuser. But it is also possible that the palm tree pollinates itself: the pollen from the male flowers could trickle down onto the female flowers - without any external influence.
And what is the purpose of the palm tree? "We don't know for sure if she derives any specific benefit from it. It could serve as a protection against environmental influences and predation by animals. Another benefit could be that the offspring germinate in an environment that has already proven itself for the parent plants. "
Kuhnhäuser spoke of a "very special discovery that you only make once in a lifetime". The palm raises tons of questions that are still unresolved. "We often see space and the depths of the sea as the limits of our world's exploration, but this new species of palm teaches us that some of the most fascinating creatures are still just beneath our feet, waiting to be discovered."